Effect of annealing on microstructure in railway wheel steel

Abstract Railway wheels are commonly made from medium carbon steels (~0.55 wt.% C), heat treated to a near pearlitic microstructure with 5–10% pro-eutectoid ferrite. During the operation of freight trains, where block brakes used, high thermal loads occur together contact stresses, which combined can affect mechanical properties material. In this study, effects annealing on local and in railway wheel steel were investigated using electron microscopy micro-hardness. It is found that after at 650 °C, room temperature hardness reduces about 25%, accompanied by significant spheroidization cementite colonies, though size orientation gradients colonies have not changed much. The relationship between microstructural changes discussed.